Biopsy device for removing tissue specimens using a vacuum

ABSTRACT

A biopsy device for taking tissue samples, includes a housing, a removable element and a control panel. The housing contains an electric power source and a tension slide connected to the power source. The tension slide may be brought into a cocked position against the action of a spring by the power source. The removable element is configured for insertion into the housing and includes a biopsy needle unit, a vacuum pressure-generating device and a control panel. The removable element may be provided as a sterile package unit. The biopsy needle unit can be arranged on the tension slide and includes a hollow biopsy needle with a sample removal chamber and a cutting sheath. The biopsy device can be held in one hand and is fully integrated with all components required to perform a vacuum biopsy such that no cables or lines are required to other external units.

This is a continuation of prior application Ser. No. 10/500,522, filedApr. 6, 2005, which claims priority as a 371 application ofPCT/DE2003/00844, filed Mar. 17, 2003, which claims priority toDE20204363.0, filed Mar. 19, 2002, DE20204362.2, filed Mar. 19, 2002,DE20204361.4, filed Mar. 19, 2002, DE10212156.7, filed Mar. 19, 2002,DE10212139.7, filed Mar. 19, 2002, DE10212155.9, filed Mar. 19, 2002,DE20209525.8, filed Jun. 19, 2002, DE20209530.4, filed Jun. 19, 2002,DE20211934.3, filed Aug. 2, 2002, and DE20215962.0, filed Oct. 17, 2002,the entireties of which are hereby incorporated by reference.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a national stage application under 35 USC §371 of InternationalApplication PCT/DE03/00844, filed on Mar. 17, 2003, the entire contentsof which are incorporated by reference herein.

FIELD OF INVENTION

The invention pertains to a biopsy device for taking of tissues samples,which consists of a hand piece, in which a hollow biopsy needle isinserted, wherein a portion of the biopsy needle protruding from thehand piece is introduced with its sampling chamber into the tissue beinginvestigated and the tissue is sucked into the sampling chamber byvacuum and then separated by a sample separating mechanism and finallyremoved.

BACKGROUND OF INVENTION

A method and a device for cutting out tissue is already known fromBritish Patent Publication No. GB 2018601A, in which the tissue in thebiopsy needle is sucked into a cutting region under vacuum influence. Inorder to create a vacuum in the hollow needle, the hand piece in whichthe hollow needle is integrated is connected via lines to a vacuumgenerator situated outside of the hand piece. The cutting off of thesample is done via a cutting mechanism, which is arrangedlengthwise-moveable in the hollow needle. The sample cut off is kept inthe needle. After pulling the needle out from the tissue, the cut-offsample is flushed out from the tip of the needle; therefore, the handpiece is connected via other lines to devices situated outside the handpiece. The vacuum established in the hollow needle is regulated bycontrol elements integrated in the lines.

Another biopsy mechanism is known from European Patent Publication No.EP 0890 339 A1, in which the sample is removed under vacuum influence.In the hand piece, in which the biopsy needle with cutting mechanism isintegrated and inserted, the biopsy needle is connected via hoseconnections and lines to an external vacuum generator as well as controldevices. The vacuum is brought up from below to the sample removingchamber via a channel molded onto the outer sheath of the biopsy needle.The separating device is arranged lengthwise moveable in the hollowspace of the biopsy needle. By a rotary movement, combined with a manuallengthwise push, the separating device cuts the sample from the tissue.The sample is transported in the hollow channel of the separatingdevice. A similar arrangement is also shown by U.S. Pat. No. 5,526,822,and here in particular various vacuum feed lines to the sample removalchamber are known, such as the arrangement for cutting mechanisms, inthe hollow needle or coaxially as a cutting sheath, on the outside. Inboth biopsy mechanisms capable of removal of a sample under vacuum, thehand piece of the biopsy device is limited in its freedom of motion byat least one connection hose and/or supply cables to one or moreexternal supply units; furthermore, the mechanisms for creating thevacuum are costly, especially in regard to the regulating mechanisms.The sample is cut out by rotating separation devices which can movelengthwise in the hollow needle chamber.

Furthermore, a suction biopsy device is known from German Patent No. DE40 41 614 C1, which is fashioned as a manual device and which has apartial vacuum source as well as a biopsy cannula connection, which canbe placed in rotation by a flexible shaft located outside the handpiece. A biopsy cannula fashioned as a hollow cannula can be mounted onthe biopsy cannula connection, preferably having a revolving cuttingedge sharpened at the distal end, along whose hollow channel a partialvacuum can be applied, by means of the partial vacuum source, which isconfigured as a piston and cylinder unit, once the hollow cannula hasbeen positioned at a particular tissue point inside the body. A similarpartial vacuum-assisted biopsy device can be found in InternationalPublication No. WO 96/28097, which, though not specifying any hollowcannula placed in rotation, nevertheless has a syringe plungerarrangement located inside a manual device to create partial vacuum.

German Patent Publication No. DE 100 34 297 A1 describes, in contrastwith the above suction biopsy arrangement with only a single hollowneedle, a tissue removal endoscopy instrument, having a biopsy needlearrangement, which specifies a circumferentially sharpened hollow needleat its distal end and a hollow biopsy needle guided inside the hollowneedle, wherein the internally guided biopsy needle has a recess forremoval of a tissue sample at its distal end. Proximal to the hollowbiopsy needle is a suctioning instrument for creating a partial vacuum.A removal of tissue occurs in that the biopsy needle arrangement ispushed in a joint position into a region of tissue being investigated,while the biopsy needle has a distal tip, which protrudes distally fromthe hollow needle for a length in order to facilitate the process ofpenetration of the biopsy needle arrangement into the tissue, on the onehand, and to prevent tissue from getting into the interior of the hollowneedle, on the other hand. When the biopsy needle arrangement issuitably positioned inside the tissue, the hollow needle is pulled backproximally for a particular length, while the interior biopsy cannularemains in position and the recess is made free. The partial vacuumapplied along the biopsy needle produces an active lowering or drawingof surrounding tissue parts into the recess. By controlled distalpushing of the hollow needle with its sharpened distal end beyond thebiopsy needle, a portion of the tissue is separated and enclosed insidethe recess of the biopsy needle. Then, by joint withdrawal of the biopsyneedle arrangement, the separated tissue sample is removed from the bodyfor examination purposes. The entire tissue removal process describedabove occurs in such a way that the needle movements and the applicationof partial vacuum are performed manually, individually and separatedfrom each other.

On the other hand, the biopsy needle arrangement described inInternational Publication No. WO 98/25522 enables a spring-operatedrelative motion between the hollow biopsy needle, located on theinterior, and the outer hollow needle surrounding the biopsy needle. Inthis case as well, the biopsy needle is positioned distally to thesharpened distal tip of the hollow needle in order to take a sample,there being provided a partial vacuum source for supplying a partialvacuum through the hollow biopsy needle into the area of its recess,assisting the process of bringing in the tissue. The process ofpositioning the biopsy needle relatively and finally inside the regionof tissue being investigated is done exclusively manually. Such apositioning leads only to unsatisfactory biopsy results, especially wheninvestigating hard tissue regions.

Likewise, a vacuum-assisted biopsy device is described in US PatentPublication No. 2001/0011156 A1, which calls for a compactly configuredhand device, in whose housing all drive elements necessary forpropelling the needle of the biopsy needle arrangement are provided.However, a partial vacuum source is provided separate from the handdevice, which can be connected via an appropriate supply line to theneedle arrangement inside the hand device at a suitable connectionlocation.

SUMMARY OF INVENTION

Starting with German Patent Publication No. DE 100 34 297 A1, which isconsidered to be the closest state of the art, the vacuum biopsy devicefor removal of tissue is based on the problem of configuring the handpiece so that the sample removal sequence can be operated with one handafter being inserted by means of a coaxial cannula, or with no suchcannula. The advantages of the familiar high-speed biopsy gun withoutvacuum, namely, the quick penetration of the needle unit, carrying thesample removal chamber into the tissue being sampled, should be retainedin addition to providing a vacuum generating device that is simple,reliable, and uncomplicated in structure. The removal of the sampleshould be such that the pathologist obtains a sufficient quantity ofuntwisted tissue for evaluation.

The solution of the invention therefore comprises a tension slide thatis brought into cocked position by electric motor power against theaction of a spring, the needle unit being arranged on the tension slidemounted in the hand piece, wherein the sample removal chamber is shotinto the tissue after releasing the cocked tension slide. The vacuumpressure-generating device, as well as other control and supply devices,are integrated in the housing of the hand piece, and the connectionelement, from the biopsy needle to the vacuum pressure-generating unit,is arranged directly on the housing. The vacuum pressure-generatingdevice comprises a controllable piston/cylinder unit, having aventilation opening, so that excess pressure can be generated in thevacuum pressure-generating device for ejection of the sample. All driveunits are electrically operated, and the drive unit for the tensionslide may also be used as the drive unit for the cutting sheath. Thehollow biopsy needle is surrounded by an exterior coaxial cuttingsheath, and at the front side of the housing there is arranged a boardfor actuating the electronics, in which the tension slide release isintegrated.

By arranging all necessary devices in the hand piece, the hand piece isfreely moveable; furthermore, high-speed electrical drive units are usedexclusively, and the tension slide and the sample separating device areoperated by the same drive unit. This produces a compact device,independent of other supply units. The drive units can be accommodatedin a relatively small housing. Even the electronics and the operatingand measuring instruments are arranged on the housing, or accommodatedin it. This also applies to the power supply and the connectionelements. It is therefore possible to bring together partial processesinto a single control step and simplify the attendance, so that theattendance can be done with only one hand.

For an especially simple and reliable configuration of the vacuumgenerating device, the use of a piston/cylinder unit with ventilationpossibility to create the vacuum and the excess pressure works well.Especially advantageous is the use of a familiar syringe/plunger unit,with a ventilation opening arranged in addition in the upper part of thesyringe body, which is opened in order to dissipate the vacuum byfurther retraction of the syringe plunger. By controlling the spindledrive unit of the plunger spindle, the same plunger/syringe unit can beswitched as needed from generating a vacuum to generating an excesspressure, using, to dissipate the vacuum, a ventilation opening arrangedin the upper part, through which air flows in, and is compressed in thefollowing step.

In order to control the motion of the plunger, especially in regard toswitching from creation of a vacuum to dissipation of a vacuum andgenerating of excess pressure, a spindle drive with electric DC motorwith secondary reduction gearing has proven to be advantageous as thedrive unit. The measured speed of revolution of the motor represents adirect measure of the lengthwise displacement of the plunger. Since thisis a high-speed DC motor, whose take-off speed is considerably reducedby a reduction gearing, the lengthwise motion of the spindle can becontrolled exactly. The length of the spindle travel and thus themagnitude of the vacuum and the excess pressure can be set withappropriate setpoint values in the control electronics, e.g., the speedof revolution of the motor.

Since a sterile biopsy needle is used for each patient, it has proven tobe advantageous to separate the sterile parts from other merelydisinfected parts that are firmly connected to the hand piece. For thisreason, it is convenient to design the vacuum pressure-generatingdevice, the biopsy needle with cutting sheath and the parts connected tothe biopsy needle and cutting sheath, such as the biopsy needle carrier,the drive elements and plastic piece including connection element andguide roller as an independent, easily inserted and removed sterileinsert element. The space for the insert element is separated from theother drive elements by covers, for reasons of cleaning of the handpiece.

For sake of simplicity, the flexible connection element is fashioned asa flexible hose, so that it can adapt to the displacement travel of thetension slide. In order to allow for twisting of the hose relative tothe biopsy needle at the proximal end, an additional rotary mountedplastic piece is arranged in the plastic piece firmly connected to thebiopsy needle, to which the hose is attached. In order to enable alengthwise movement of the gear connected to the spindle casing fordriving of the spindle casing, e.g., when the tension slide is released,a toothed roller is provided as the drive unit. In order to provide fora cocking of the tension slide via the biopsy needle carrier by turningthe cutting sheath, the gear at the end face of the threaded spindlecasing is supported against a holder of the base block during thecocking process, so that the biopsy needle carrier moves to the right,while the cutting sheath maintains its position.

The locking of the tension slide has a double-arm lever, whose one armengages under spring pressure with the recess of the tension slide. Inorder to allow for use of the tension device for different biopsyneedles with different insertion depths, e.g., 15 to 25 mm, it is onlynecessary to adapt the length of the engaging lever and use appropriatesettings in the electronics, for example. The plastic piece joined tothe biopsy needle enables a turning of the sample removal chamber bymeans of a knurled disk. The biopsy needle can be locked in the desiredposition by the interaction of the polygon of the plastic piece and thebiopsy needle carrier. A notch made in the knurled disk shows the userthe radial position for the opening of the sample removal chamber.

The cross section of the hollow biopsy needle is limited by a narrowing,a stuffing, or a lip at the sample removal chamber. This narrowing isaround 60-75% of the height and closes off the upper open part of thesample removal chamber from above. This narrowing in front of the sampleremoval chamber has the effect that the vacuum sucks in the tissue beinginvestigated from the bottom—upon opening of the sample removalchamber—(i.e., upon retraction of the cutting sheath). The narrowing inaddition prevents tissue from getting into the rear part of the hollowneedle space. When the sample is ejected, the narrowing produces apressure increase in the sample removal chamber, which improves thecleaning effect, especially in the sample removal chamber. By applyingthe vacuum, the tissue of the sample is sucked into the interior of thesample removal chamber and clings more or less to the inner wall. Forbetter adhesion, additional means can be provided in the interior of thesample removal chamber. Since the cutting sheath is arranged on theouter diameter of the biopsy needle and thus the separation of thetissue occurs externally, the tissue clinging to the inner space is notdetached from the inner wall by the cutting mechanism, thanks to theexternal arrangement of the cutting sheath. Furthermore, the tissuecannot get into the cavity of the rotating cutting mechanism and getstuck inside. Guiding of the cutting sheath with its round cross sectionon the outer side of the biopsy needle with its round cross section hasthe advantage that no twisting (turning) of the sample can occur by thecutting rotation of the cutting mechanism, thus fulfilling a majorrequirement for the evaluation of the tissue by the pathologist. Inorder to achieve a good adhesion of the sample in the inner spacewithout impairing the fill ratio, the sample removal chamber isconfigured so that approximately 25% of its cross section is open forsuctioning in the sample, i.e., the larger portion of the circumferenceis closed.

The arrangement of the coaxial cutting sheath on the outside also hasthe effect that a larger sample can be removed than when the cuttingsheath is arranged on the inside. Since the sample is ejected withassistance from a pressure built up from the sample removal chamber, nodamage to the tissue occurs when taking the tissue out. Thanks to thecentral arrangement of the base block at the center of the inner chamberof the housing, the housing itself is protected against transverseforces produced by the drive elements. Furthermore, it is easy toreplace the drive units, as well as the tension slide, since it is onlynecessary to loosen the connections to the housing for this. It is alsoadvantageous that the impacts produced by the plastic tension slide areabsorbed by the base block.

The storing of the biopsy needle/cutting sheath in a biopsy needlecarrier made of plastic has the advantage, among others, that themolded-on sliding surfaces enable a trouble-free sliding on the opposingsurfaces of the base block and the molded-on block. The biopsy needlecarrier transmits the forces from the spindle drive of the cuttingsheath to the tension slide. Since the spindle drive thrusts against theholder of the base block when the tension slide changes position and itcan slide freely when the tension sheath is rotated (the gear can slideaxially in the toothed roller), the drive unit can be used for bothmotion sequences (tensioning of the tension slide, opening and closingof the sample removal chamber by means of the cutting sheath). Theminiature switch integrated in the housing end piece, which turns thepower supply off and on by the closing of the housing cover with thevacuum pressure-generating device inserted, as well as the retainingtabs arranged on the biopsy needle carrier, are safety mechanisms whichprevent a tensioning of the tension slide when the housing cover isopen. Furthermore, an opening of the housing cover when the needle isunder tension will be precluded.

The guide roller, mounted in the end cover of the housing with thebiopsy needle and cutting sheath passing through it, cooperates with thecannula which has been inserted into the tissue. Because a seal elementis placed on the proximal end of the previously mounted coaxial cannula,interacting with the cutting sheath, air is prevented from getting inbetween the cannula and the cutting sheath. The guide roller placed onthe cannula prevents the inner housing from getting dirty and preventsthe nonsterilized hand piece from touching the coaxial cannula. Theboard arranged on the hand piece with integrated light-emitting diodesand switches, as well as icons, accomplishes a simple operator guidance.The cover plate can also be used as a carrier for miniature switches orphotocells. The insertion aid enables easier insertion of the sterilizedreplacement element.

In order to make sure that the tissue is reliably cut through when thesample removal chamber is closed, the cutting sheath travels byapproximately 2 mm out toward the tip of the needle, beyond the distalend of the sample removal chamber. To prevent operator error, thesequences “cocking of the tension slide” and “ejection of sample” areprovided with delay circuits. To enhance the safety, it may be advisableto select a different color for the light-emitting diodes in the case ofprocesses taking place in the tissue, such as “separate the sample”,than that for processes taking place outside the tissue, such as “ejectthe sample”.

When using a coaxial cannula in which the needle unit is inserted, so asto achieve an exact positioning, for example, one must make sure that noair can get in between the outer circumference of the needle and theinside of the coaxial cannula when a vacuum is produced. Therefore, aseal element is provided at the proximal side of the coaxial cannulatube. Since the depth of insertion of the needle unit is dictated by thecocking distance of the tension slide, unless means are provided in thehand piece for different depths of insertion, the use of spacing piecesbetween the coaxial cannula and guide roller has proven to be especiallyadvantageous. The spacing piece is strung onto the needle unit and sitsdistally on the proximal end of the coaxial cannula, and proximally on aguide roller arranged in the hand piece. As a result, for the sameinsertion length dictated by the device, the depth of penetration isreduced by the length of the spacing piece, resulting in easierproduction conditions.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention shall now be described as an example by means of sampleembodiments making reference to the drawings, without limiting thegeneral notion of the invention.

FIG. 1 shows a biopsy device with open housing cover (perspective view).

FIG. 2 shows a unit of the biopsy device which is fixed to the housing(without bottom of housing and cover) and the replaceable biopsy unit;shown separately (perspective view).

FIG. 3 shows a lengthwise section A-A through the biopsy needle of FIG.1.

FIG. 4 shows a cross section A-A in FIG. 3 (left housing part).

FIG. 5 shows a cross section B-B in FIG. 3 (right housing part).

FIG. 6 shows a right housing end cover (inside) with integratedminiature switch.

FIG. 7 shows a front side of board.

FIG. 8 a shows a base block in X-axis viewed from front (perspective).

FIG. 8 b shows a base block in X-axis viewed from behind (perspective).

FIG. 9 a shows a unit of the biopsy device that is fixed to the housing(without housing cover or bottom) in the uncocked condition.

FIG. 9 b shows a locking mechanism in the uncocked condition.

FIG. 10 a is the same as FIG. 9 a, but tension slide in cocked position.

FIG. 10 b is the same as FIG. 9 b, but in locked condition.

FIG. 11 a shows a side view of a biopsy needle tip.

FIG. 11 b shows a lengthwise section through FIG. 11 a (sample removalchamber opened).

FIG. 11 c is the same as FIG. 11 b, but (sample removal chamber halfopen).

FIG. 11 d is the same as FIG. 11 b, (sample removal chamber closed bycutting sheath).

FIG. 11 e shows a cross section A-A in FIG. 11 a.

FIG. 12 shows a biopsy needle carrier with press-fitted biopsyneedle/cutting sheath and plastic piece (from below, rotated around 90°,perspective view).

FIG. 13 shows a vacuum/pressure device, installation and actuation (seenfrom rear, perspective view).

FIG. 14 a shows a vacuum/pressure device with plunger mounted on thebottom of the syringe (starting position for creating a vacuum and endposition for generating pressure, partially cut away).

FIG. 14 b shows a vacuum/pressure device with retracted plunger; endposition of the vacuum stroke (partially cut away).

FIG. 14 c shows a clearing of the ventilation opening (syringe plungerretracted beyond ventilation opening; pressure equalization position,partially cut away).

FIG. 14 d shows a cross section A-A through the threaded spindle in FIG.14 c.

FIG. 15 shows a base block and biopsy needle/cutting sheath, preparedfor fitting out with photocells and miniature switches to detect actualvalues.

FIG. 16 shows an insert element lifted off from the insert aid(perspective view).

FIG. 17 shows an insert aid (perspective view).

FIG. 18 shows a coaxial cannula and spike (exploded view).

FIG. 19 shows a section through the cap of a coaxial cannula.

FIG. 20 shows a coaxial cannula with inserted needle unit.

FIG. 21 shows a coaxial cannula with inserted needle unit making use ofa spacing piece.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description should be read with reference to thedrawings, in which like elements in different drawings are identicallynumbered. The drawings, which are not necessarily to scale, depictselected preferred embodiments and are not intended to limit the scopeof the invention. The detailed description illustrates by way ofexample, not by way of limitation, the principles of the invention. Thisdescription will clearly enable one skilled in the art to make and usethe invention, and describes several embodiments, adaptations,variations, alternatives and uses of the invention, including what ispresently believed to be the best mode of carrying out the invention.

Integrated in the housing interior of a hand piece 1 are all devicesrequired to perform a vacuum biopsy (FIG. 1), so that no cables or linesare required going from the housing of the hand piece to other externalsupply devices. Thus, the hand piece 1 constitutes a complete vacuumbiopsy device, which is freely moveable in all directions.

From the distal part of the left end cover 6 protrudes the distal partof the hollow biopsy needle 2 with the cutting sheath 3 surrounding itcoaxially, which is required to remove the tissue sample. Usually, acoaxial cannula is placed in the tissue, into which the biopsy needle 2with cutting sheath 3 is introduced. Outside the right end cover 7 ofthe housing there is arranged a connection element 4, e.g., atransparent flexible hose, which connects the vacuum pressure-generatingdevice 5, arranged in parallel with the biopsy needle, to the interiorcavity of the biopsy needle 2. The hollow connection element 4 issituated in immediate proximity to the end cover 7 of the housing. Thebiopsy needle with cutting sheath and additional elements, arranged in abiopsy needle carrier 37, forms together with the connection element 4and the vacuum pressure-generating device 5 an element 20, easilyinserted or taken out at the top, which is replaced as necessary (FIG.2). The housing cover 10 is opened for this purpose. As FIG. 2 inparticular shows, the biopsy device can be divided into parts which arefirmly connected to the housing (disinfected parts) and a removableelement 20 (sterile part). While the parts firmly connected to thehousing are merely disinfected, the removable element 20 comes in asterile package and can be replaced as necessary, especially for eachnew patient.

In the sample embodiment described hereafter, the vacuumpressure-generating device is arranged in parallel with the biopsyneedle. However, in the scope of the invention, the vacuumpressure-generating device can also be arranged lying in the axis of thebiopsy needle or the hand piece; neither does it require its ownconnection element, if for example it is mounted directly on the end ofthe biopsy needle.

Between the left and right end covers 6, 7 of the housing is the lowerpiece 9 of the housing and a housing cover 10 which is hinged in the endcovers of the housing, with a locking latch 11. By means of tie rods orscrews, which are partly screwed into a base block 8, the lower piece 9of the housing is clamped between the end covers 6, 7, or it is joinedto the base block 8. The housing cover 10 can swivel about an axissecured in the end covers 6, 7 of the housing. The housing cover 10 isclosed before the biopsy mechanism is used; the inner contour of thehousing cover corresponds to the outer contour of the biopsy needlecarrier 37, which will be described more precisely hereafter.Approximately at the center of the interior space of the housing isarranged the base block 8, which is firmly connected to the lower pieceof the housing, for example, by fixation elements and/or by a screwconnection. The base block 8, which extends not only in the lengthwiseaxis from the middle to the left, but also across the entire transversesurface, is connected to the drive elements for the vacuumpressure-generating device 5, the cutting sheath 3 and the cockingmechanism for the tension slide 28, on which the biopsy needle carrier37 is mounted. Furthermore, the base block 8 has a holder 36, open atthe top, for the biopsy needle/cutting sheath, and an additional insertelement 62 for the vacuum pressure-generating device.

In order to specify the position of the individual elements, as well asthe position of the individual parts, especially in the interior of thehousing, a coordinate scale has been drawn in FIG. 1, the midpoint ofthe coordinates lying at the center of the base block 8 (FIG. 1).Accordingly, for the following description and for the claims, movementindicated in the direction of the X-axis is considered left (distal) andmovement indicated away from the X-axis is considered right (proximal).For the other coordinates, movement in the direction of the Y-axis isconsidered top, movement away from the Y-axis is considered bottom,movement in the direction of the Z-axis is considered rear, and movementaway from the Z-axis is considered forward (FIG. 1). Thus, thecoordinate system divides the interior of the housing and the otherreferences into left and right, forward and rear, and top and bottom.

Making reference to these remarks, in the bottom, front, left part ofthe housing interior are found the joint actuating mechanisms 106 forthe cocking mechanism and the cutting sheath, and in the bottom, rear,left part of the housing is the actuating mechanism 105 (FIG. 13) forthe vacuum pressure-generating device 5. In the bottom right part isaccommodated the energy supply for the actuating motors and the otherelectrical parts, such as for the control and/or monitoring elements;preferably, batteries or a storage battery 111 are used for this, e.g.,a 7.2 V lithium ion battery, 1 Ah. The forward, right, top interiorspace of the housing lying above the battery compartment is utilizedmainly for the tension slide 28 with locking piece (FIG. 5); this isconnected to a block 26, which is part of the base block 8. The batterycompartment is sealed on top by a separation plate 114.

In the uppermost front part of the housing interior there is arranged abiopsy needle carrier 37, which can be inserted into and taken out fromthe U-shaped insert holder 36 of the base block 8, which is open at thetop, and the bracket 40 arranged on either side of the tension slide 28and pointing upward; the biopsy needle/cutting sheath unit withactuating parts is moveably mounted in this, extending for almost theentire length of the hand piece. This means that, in the uncocked state,the left end surface of the biopsy needle carrier 37 lies against theleft end cover 6 of the housing, and in the cocked state the right endsurface lies against the right end cover 7. “Almost the entire length”means that the biopsy needle carrier is at least shorter by the distancerequired in the interior of the housing for the cocking sequence. If thecocking distance of the tension slide is 20 mm, for example, the biopsyneedle carrier must be able to move by this amount. In general, thecocking distance is between 15 and 25 mm, depending on the biopsy needleused. It is therefore advisable to design the interior for the longestpossible cocking distance.

The cocking device (situated right front) itself consists of a tensionslide 28, placed on a bolt 30, the bolt screwing into the base block 8.The bolt 30 has a spiral spring 31 surrounding it. The locking device(see especially FIGS. 9 b and 10 b) of the tension slide is secured tothe block 26. In the top, rear, right interior of the housing isaccommodated the vacuum pressure-generating device 5 with parts of theactuator; the actuating motor with reduction gearing for the vacuumpressure-generating device is located in the left, bottom, rear area ofthe housing interior.

The hand piece, and also in particular the biopsy needle or the vacuumpressure-generating device, are not connected either by cable or hoselines to additional supply units situated outside of the housing handpiece. Therefore, the mobility and maneuverability is not impairedeither by lines or by cables. The housing cover, the bottom piece of thehousing, the end covers of the housing and the base block consistpreferably of aluminum.

The hand piece 1 consists, as already specified, of a housing, which isformed from a housing lower piece 9 with side walls raised to differentheight, the housing cover 10 adapted to the lower piece of the housingwith lengthwise moveable locking latch 11, and the two end covers 6 and7. The lower piece of the housing is joined to the two end covers by tierods or screws, e.g., made of iron, which are partly screwed directlyinto the base block 8. The housing is around 200 mm in length, the endcovers have approximately square cross section, roughly 40×40 mm (FIG.2). The housing cover 10 can swivel about an axis 104, which is securedin the end covers 6, 7; boreholes 14 in the end covers are used forthis. The dog 12 of the locking latch 11 can be pushed into the recess45 of the base block 8 to close the housing cover.

The left end cover 6 has, in the upper forward part, an upward openU-shaped passage 13 for the forward protruding part of the biopsyneedle/cutting sheath 2, 3 and the guide roller 81 mounted thereon. Therear end cover 7 of the housing has two upward open U-shaped passages15, 16. The passage 15 corresponds to the passage 13; it receives theend of the plastic part 47, with round cross section, mounted on thehollow biopsy needle. In passage 16 is inserted a connection piece 63for the vacuum pressure-generating device (FIG. 2). An additionalplastic part 112, inserted in the plastic part 47, has a plug 17 whichis used to connect the connection element 4 to the outlet connector 64of the vacuum pressure-generating device. The inner cavity of the biopsyneedle is connected continuously to the cavity of the plunger/cylinderarrangement and the cavity of the vacuum pressure-generating device. Theconnections are configured such that neither can air get into the systemfrom the outside nor can air flow out when excess pressure prevails;thus, the connection points are air-tight. As FIG. 6 shows inparticular, a miniature switch 18 is integrated in the passage 16 of theright end cover 7 at the bottom side, whose switch pin 19 protrudes intothe passage. As soon as the connector 63 of the vacuumpressure-generating device is inserted in the passage and the housingcover is closed, the switch pin 19 of the miniature switch 18 is presseddownward and the miniature switch 18 allows current to flow. Terminalsfor hooking up a charger can be built into the passages 97, 98 of theright end cover 7.

At the front side of the bottom piece 9 of the housing there is asurface 113 provided for the board with the operating and monitoringelements (FIG. 1). The board 57 secured to the housing is designed as anindependent component, which is glued, for example, onto the surface 113of the bottom piece 9. This board 57 is connected by lines to otherelectronic components arranged in the housing, and to the power supply.The board contains in particular switches for the operation and diodesfor the monitoring. The activating button 88 for mechanical triggeringof the cocked tension slide protrudes through a recess 65 in the bottompiece of the housing and the board.

When configuring the operating and monitoring elements consideration wasgiven to the difference between the cocking sequence of the tensionslide and the triggering of the tension slide, on the one hand, and theperformance of the biopsy, such as the cutting out of the sample, aswell as the removal of the sample with the ejection of the sample, onthe other hand. Accordingly, the activating button 88 (trigger) for thetension slide has been placed at the right and the cocking button 90 forcocking the tension slide is at left. The program button 89 forperforming the biopsy is in the middle. It is necessary to press theprogram button for three functions. The first function, start or reset,is indicated by the reset diode 91, while the sample removal diode 92arranged underneath indicates the opening and closing of the sampleremoval chamber when removing the sample. The lowermost eject diode 93indicates the ejection of the removed sample. The cocking diode 94indicates the cocking of the tension slide; the locking diode 95indicates the locking of the tension slide. The battery charge diode 96indicates the charge condition of the battery or storage battery. Thediodes are switched so that the diode blinks while performing theparticular sequence and after completion of the sequence the dioderemains lit. When there are two possible choices, both diodes are lit.The operator is then free to make a choice. The mode of operation andpossibility of control shall be examined more closely in detail whendescribing the sequence. Symbols (icons) at the margin symbolize theindividual processes.

To improve the operating safety it may be advisable to outfit individualautomated sequences with delay circuit. In particular, it has been foundthat the processes of “cocking of the tension slide” by pressing thecocking button 90 and “ejection of sample” by pressing the programbutton 89 are provided with delay circuits of around 1.2-1.5 seconds toimprove the operating safety. Furthermore, the operating safety isimproved when the light-emitting diodes indicating the individualprocesses have different colors for processes outside and processesinside the tissue.

A perspective representation of the base block 8 (looking from the frontin the direction of the X-axis) is shown by FIG. 8 a; the base block 8is shown from the rear in the X-axis by FIG. 8 b (both of themperspective views). The base block 8 can be divided into two halves,looking in the lengthwise direction; the front part serves to secure thejoint actuation for the cutting sheath and tension slide, and also inits upper part to mount the biopsy needle carrier (FIG. 8 a); the rearpart serves to secure the actuation for the vacuum pressure-generatingdevice and to mount one side of the vacuum pressure-generating device(FIG. 8 b). Between the two actuating motors 21, 58, beneath the centerrib 87, is arranged a central electronic board. The base block 8 has inits left front part a U-shaped space 24, in which is installed a toothedroller 23, driven by the gear motor 21. For this, the take-off shaft ofthe gear motor is mounted or inserted in an opening in the wall 25 ofthe base block 8. The toothed roller 23 is mounted on the take-off shaftand secured to it, for example, by means of a screw, so that it cannotturn or shift. At the other end, the toothed roller 23 is mounted in thewall 22 of the base block 8. The actuating motor used is a DC motor witha speed of around 11000 rpm. The DC motor is connected to a planet gearwith high reduction ratio, on whose take-off shaft the toothed roller 23is mounted.

An additional block 26 is molded on the wall 22, pointing to the right,which accommodates both the swiveling double lever 33 for the lockingprocess and also serves to fasten the bolt 30 for guiding the tensionslide 28. The bolt 30 is screwed into the threaded borehole 29. Duringthe cocking process, the tension slide 28 moves to the right on the bolt30 and the separating plate 114 is arranged underneath. The spiralspring 31 arranged on the threaded bolt 30 is compressed during thecocking process. At one end, the spiral spring thrusts against an endpiece 32 of the threaded bolt or directly against the end cover 7 of thehousing; the other end of the spiral spring thrusts against the end ofthe guide borehole 115 of the tension slide.

The tension slide 28 moves on the threaded bolt and the separating plate114 and is thus prevented from twisting. One arm 99 of the double-armlever 33 of the locking device engages with a groove 27 of the tensionslide 28 (FIGS. 9 a and 10 a). The locking device, integrated in theblock 26 of the base block 8, consists of the double-arm lever 33, whichcan swivel about an upright axis 35 (looking in the Y-axis) by means ofa compression spring 34. The axis 35, an upright pin, is secured in theboreholes 38 of the base block. In the uncocked condition, the part 99of the double-arm lever lies in the groove 27 of the tension slide; thecompressed spring 34 acts on the part 100 of the lever to press thelocking button 88 outward (forward). As soon as the part 99 of thedouble-arm lever can engage in the recess 82 of the tension slide, theactivating button 88 is pressed outward. The tension slide is locked bythe locking of the lever part 99 in the cocked condition and can now betriggered when necessary with the activating button 88. Since thetension slide is advisedly made of plastic, it has proven advisable toemploy a metal part 83 in the recess, so as not to damage the plastic,since the double-arm lever is made of metal. Unlike the removableelement 20, the hand piece 1 with replaced insertion element can be usedrepeatedly. The cocking distance corresponds to the depth of penetrationof the biopsy needle into the tissue. Hence, the length of the lever 99likewise corresponds to the cocking distance. Since the depth ofpenetration is generally between 15 and 25 mm, the same hand piece 1 canbe used for different depth of penetration by appropriately configuringthe length of the lever 99 and changing the setpoints of the controlsystem.

The tension slide 28, which adjoins the block 26, is arranged at equalheight and is roughly equal in cross section. On its top side, thetension slide has two brackets 40. The upward pointing surface 41 of thetension slide, as well as the upward pointing surface 44 of the block26, and the upward pointing surface of the extension 42 of the basicblock 8, together form a planar bearing surface for the lower slidingsurface 43 of the biopsy needle carrier 37 mounted thereon. The biopsyneedle carrier is made of plastic. As the tension slide is moved fromthe starting uncocked condition (FIG. 9 a) to the cocked condition (FIG.10 a), i.e., to the right, the biopsy needle carrier 37 held by thebrackets 40 slides across the surface 42 and 44. It is also conceivablethat the sliding surfaces are configured not planar, as in the sampleembodiment, but instead have specially configured sliding surfaces; theimportant thing is that the biopsy needle carrier 37 can slide easilyand straight on the sliding surface and the biopsy needle can penetratestraight into the tissue, or tumor, after triggering the activationbutton 88. Therefore, the upper outer contour of the biopsy needlecarrier is also configured correspondingly to the inner contour of thehousing cover and has only slight play relative to the housing cover inorder to prevent the biopsy needle from deviating upward.

Above the U-shaped space 24 for the toothed roller 23, at the height ofthe sliding surface 42, the basic block 8 has a U-shaped upwardly openholder 36, for inserting the biopsy needle/cutting sheath among otherthings. This holder serves primarily as a radial thrust bearing, i.e.,as a prop for the actuating part connected to the cutting sheath, thegear 74, or the plastic disk 78, in order to bring the tension slideinto its cocked position by means of the actuating device 106, as shallbe described afterwards. In the upper rear part of the base block thereis provided another U-shaped insert element 62, in which the free end 61of the threaded spindle of the vacuum pressure-generating device 5 isinserted. In the middle, top, of the base block 8 is the recess 45, intowhich the dog 12 of the locking latch 11 of the housing cover is forced.A cover 46 arranged on the base block 8, pointing to the left, separatesthe space of the actuating motors and the board from the upper left partof the housing interior, which is used primarily to keep theexchangeable biopsy needle carrier 37, including biopsy needle andcutting sheath. The cover 46 protects the electric gear motors and theboard against dirt. The board for the electronics lies between theactuating motors and underneath the middle rib.

FIG. 2 shows the biopsy needle carrier 37, which can be inserted intothe brackets 40 of the tension slide 28 with biopsy needle 2 and cuttingsheath 3, as well as other parts. The hollow, round circular biopsyneedle 2 has a needle tip 70, which adjoins the sample removal chamber71 (FIG. 11 a-11 e). The biopsy needle 2, which is round in crosssection, is surrounded by a coaxially arranged cutting sheath 3, roundin cross section, having a cutting edge 72 at its left end, facing thesample removal chamber, which serves to cut out the tissue sample afterthe biopsy needle is introduced (with sample removal chamber closed) andafter the sample removal chamber is opened and the sample is sucked intothe sample removal chamber. The cutting edge preferably standsperpendicular to the lengthwise axis of biopsy needle and cuttingsheath. The cutting process occurs by rotation and simultaneouslengthwise displacement of the cutting sheath by means of the threadedspindle drive. It is also conceivable that the motion occurs notcontinuously, but stepwise or vibrating, i.e., the feed process movesback and forth with short intervals.

At the other, proximal end of the cutting sheath, away from the cuttingedge 72, there is fastened a threaded spindle casing 73 with a gear 74arranged at the end face of the threaded spindle casing. The threadedspindle casing with gear is arranged on the cutting sheath and preventedfrom turning and shifting. The threaded spindle cooperates with athreaded spindle nut 75, which is firmly press-fitted in the biopsyneedle carrier 37. The gear 74 lies to the left, i.e., before thespindle casing begins. When the threaded spindle casing is turned bymeans of the gear 74, the cutting sheath is rotated and shifted inlengthwise direction along the biopsy needle 2.

The gear 74 at the left end of the threaded spindle engages with thetoothed roller 23 after the biopsy needle carrier is inserted in thebrackets 40. So as to allow for inserting the biopsy needle carrier 37into the brackets of the tension slide when the slide is not cocked(FIG. 2), the biopsy needle carrier has two plane parallel recesses 77.When the sliding surface of the biopsy needle carrier 37 is placed onthe surfaces 41, 42 and 44, at the same time the cutting sheath isinserted in the holder 36 of the base block 8. To improve the turning ofthe spindle drive, especially when the holder 36 is used to support thecocking of the tension slide, a plastic disk 78 can be inserted at theleft side of the gear, being provided with a slight cone. When thebiopsy needle carrier is correctly inserted, it slides to the right bythe sliding surface 43 over the surfaces 42 and 41 when the tensionslide is cocked. Since the specimen removal chamber is only closed afterinserting the biopsy needle carrier, the gear 74 bears against theholder 36. Now, if the toothed roller 23 is driven further in the samedirection, the threaded spindle drive will screw the tension slide tothe right along the biopsy needle carrier, until it locks; the biopsyneedle will be pulled inward, while the cutting sheath remains in itsposition. After the locking, the cutting sheath protrudes beyond the tipof the biopsy needle. Therefore, after the locking of the tension slide,the cutting sheath is rotated back to the starting position (oppositedirection of rotation); the gear 74 will move from left to right in thetoothed roller. After releasing of the tension slide, the biopsyneedle/cutting sheath with gear slides back to the left with the biopsyneedle carrier. Now, the cutting sheath can again be moved to the rightin order to open the sample removal chamber.

The right end of the cutting sheath is connected to the hollow biopsyneedle by a seal element 76, able to move in rotation, but air-tight, sothat neither air can get in between biopsy needle and the cutting sheathcoaxially surrounding it, nor can air escape during excess pressure. Onthe right end of the biopsy needle 2 is mounted air-tight a round,likewise hollow plastic part 47, being frictionally joined to the biopsyneedle. The plastic part 47 has a bearing element 49 at its left end,which is press-fitted into the biopsy needle carrier; at its right end,protruding from the hand piece 1, there is inserted another plastic part112, which can turn relative to the plastic part 47 and the biopsyneedle 2. Between biopsy needle and plastic part 112 there is insertedan O-ring seal. The plastic part has a plug 17 at its right end, ontowhich the connection element 4 is placed air-tight.

There is also a knurled disk 80 on the right part, protruding from thebiopsy needle carrier and the housing, by which, when rotated, theposition of the sample removal chamber can be adjusted radially, withoutaltering the position of the cutting sheath. One rotation of the biopsyneedle involves only one rotation of the sample removal chamber and,thus, the sample removal device. The plastic part 47 with biopsy needleand cutting sheath is press-fitted into the biopsy needle carrier withthe bearing element 49 and the threaded spindle nut 75. The biopsyneedle can rotate in the biopsy needle carrier and is mounted in thecutting sheath by the bearing element 49 and its narrow guide in thecutting sheath, and it can shift in the lengthwise axis with the biopsyneedle carrier. As described above, the cutting sheath is axiallymovable by rotation relative to the biopsy needle. To the right of thebearing element 49 a polygon 50 is arranged on the plastic part, whichcan lock with the biopsy needle carrier by tension, so that the sampleremoval chamber of the biopsy needle can be brought into the mostfavorable position for the biopsy removal and held there by means of theknurled disk 80.

Details of the sample removal chamber and the tip of the biopsy needleare represented in FIGS. 11 a-11 e. The sample removal chamber 71adjoining the needle tip 70 is open from above for approximately 25% ofits cross section. The cutting edges can be ground or sharpened. Thesample removal chamber is between approximately 15 and 25 mm in length.It adjoins the cavity of the biopsy needle. At the transition, ie., theright end of the sample removal chamber, the cross section of the cavityof the biopsy needle is closed between approximately 50% and 75% by anarrowing, e.g., a stopper 79 (FIGS. 11 b-11 e). The height of thestopper is chosen such that it extends downward past the recess of thesample removal chamber. In this way, the vacuum will especially draw inthe tissue sample through the continuous opening of the sample removalchamber and bring the tissue sample up against the wall of the sampleremoval chamber.

When there is excess pressure in the cavity of the biopsy needle, thenarrowing or stopper has a pressure boosting effect. The stopper hasroughly the length of 10 mm and is glued or welded into the cavity. Whenusing laser welding, it has proven to be advantageous to make the leftside of the stopper thin for a short length, around 2 mm, by removingmaterial at the end surface. As a result, in this region at the endsurface the tube of the biopsy needle is welded to the end surface ofthe stopper and is air-tight at the end surface. The stopper can also beof shorter length, as long as the same effect is achieved. Thus, thestopper can also be replaced by a lip or dog of approximately the sameheight. The important thing is that the narrowing is configured suchthat the vacuum is brought to bear primarily from the bottom in thesample removal chamber, so that the sample clings to the wall of thesample removal chamber during the cutting process and does not change inlength. It has also proven to be advantageous to provide additionalfixation means on the sample removal wall.

The suctioning of the sample from the bottom into the sample removalchamber produces, first, a high fill ratio of the sample removal chamberand, second, especially thanks to its configuration, a good fixation ofthe sample on the wall. Since the cutting sheath separates the sample atthe outside of the biopsy needle, this firm suctioning of the sampleinto the interior is also preserved during the separation process.Furthermore, thanks to the cutting sheath arranged on the outside,thanks to the vacuum applied, no tissue is suctioned into the hollowcutting sheath and thus the tissue cannot get twisted or turned by therotating lengthwise movement of the cutting sheath, as it is held fastin the interior of the cutting sheath. This improves the quality of thesample, since the pathologist obtains original material corresponding tothe cross section of the cut and not being twisted or deformed. When thesample is ejected under pressure, a complete cleaning of the sampleremoval chamber occurs in addition through the stopper 79, so that nocomingling occurs when used repeatedly. Since the vacuum generatingdevice is used at the same time as a pressure generating device, theentire cavity is cleaned, especially that of the needle.

FIG. 13 shows the drive and the installation of the vacuumpressure-generating device 5 (view from the rear, i.e., opposite theZ-axis, housing cover and lower housing piece left out). In the upper,rear, right region, the vacuum pressure-generating device 5 is arrangedas a piston/cylinder unit 69. It consists of a syringe body 52 withthreaded spindle 53 arranged inside, at whose end facing the syringebottom 51 there is fastened a plunger 54 with seal elements—as iscommonly known with syringes (FIG. 14 a-14 d). At the end of the syringebody 52 facing the base block 8, a threaded spindle nut 48 is arrangedon the threaded spindle with a gear 55 formed at the circumference. Thethreaded spindle nut has one or more thread turns. The threaded spindle53 interacts with the threaded spindle nut 48. The spindle has a pitchof around 5 mm per turn, so that at each rotation the plunger is movedout from the syringe body by a precisely defined amount, i.e., away fromthe syringe bottom 51, or toward the syringe bottom, depending on thedirection of turning.

The toothed crown 55 arranged on the circumference of the threadedspindle nut meshes with the drive pinion 56, which is fastened on thetake-off shaft of the DC gear motor 58. The take-off shaft of the DCgear motor 58 is mounted in the base block 8; for this, the take-offshaft is inserted into the transverse plate 59 of the base block. Whenthe DC gear motor 58 is activated, the plunger is moved toward thesyringe bottom or in the direction of the base block 8, depending on thedirection of turning. The drive motor used is likewise a DC motor withhigh speed, connected to a planet transmission with high reductionratio. It corresponds to the motor already described for the cockingmechanism.

The plunger 54 is configured in familiar fashion as a syringe plunger.The syringe body made from plastic, being a cylinder with a bottom, istransparent. In order to prevent a twisting of the threaded spindle 53upon actuation of the threaded spindle nut, the two opposite surfaces 60of the threaded spindle are planar in configuration (FIG. 14 d). Thethreaded spindle is inserted into the insert element by its free end.The spacing between the surfaces of the threaded spindle corresponds tothe width of the U-shaped insert element 62 of the base block 8. Thereis only slight play between the U-shaped cross section of the insertelement and the spindle surfaces at either end. The threaded spindle nutthrusts against the base block. In order to prevent the syringe body 52from sliding out upon turning of the threaded spindle nut, the bearingsurface at the base block 8 is slightly conical toward the bottom. Theconnection piece 63 of the syringe body 52 is inserted into the passage16 of the right end cover 7 so that the syringe body is held in roughlyhorizontal position.

In order to make the threaded spindle easy to turn, the threaded spindlenut with toothed crown has a chamfer 66 around 1.5 mm in thickness atthe side facing the base block. Since, furthermore, the surface of therib 59 on the base block 8, which interacts with the chamfer 66 of thethreaded spindle nut 48, is inclined from top to bottom, the vacuumpressure-generating device is pulled downward during operation. Tocreate a sufficient vacuum of around 200 hph in the sample removalchamber, for example, when using a biopsy needle with length of around250 mm and an internal diameter of the hollow biopsy needle of around 5mm, one uses a syringe body for 20 ml with a length of around 90 mm. Inorder to be able to use the syringe body also as a pressure generator, aventilation opening 67 of around 1.5 mm diameter, for example, isprovided after around ¾ of its length, corresponding to the stroke forproducing the vacuum (position per FIG. 11 b).

If the syringe plunger is moved beyond the ventilation opening 67 (FIG.14 c)—when the vacuum is no longer required—intake of air (atmosphericpressure) through the ventilation opening 67 will dissipate thepreviously established vacuum in the hollow biopsy needle. If, then, thedirection of turning of the gear motor is reversed, the vacuumpressure-generating device will build up an excess pressure in thesystem by retraction of the plunger (toward the bottom of the syringe),which brings about the ejection of the tissue sample after opening thesample removal chamber. Moreover, the pressurized air will clean notonly the sample removal chamber, but also in particular the inside ofthe biopsy needle. The stopper narrowing the cavity of the needle willmake it difficult or entirely prevent tissue parts from getting into thecavity of the biopsy needle. The narrowing of the needle cavity by thestopper 79 will increase the pressure at the sample removal chamber andthereby improve the ejection of the sample, even when the sample removalchamber is half open.

The handling of the biopsy mechanism shall now be explained more fully.The removable insert element 20, comprising a vacuum pressure-generatingdevice, elastic connection element, biopsy needle carrier with needleand cutting sheath and additional elements connected to it, alsocontains a guide roller 81 mounted on the needle. This unit, includingan insert aid, comes in a sterile package. The plunger 54 in the syringebody 52 comes slightly (1-2 mm) lifted up from the syringe bottom, thesample removal chamber 71 of the biopsy needle 2 is open so that one canmake a visual inspection of the chamber prior to inserting. Afteropening the housing cover 10, the carrier element 37, including biopsyneedle 2, cutting mechanism 3, and other parts connected with it, suchas the vacuum pressure-generating device 5 hooked up to the connectionelement 4, is inserted into the connection element provided for this(FIG. 2).

During the insertion process, one must make sure that the gear 74engages with the teeth of the toothed roller 23; the cutting sheath isinserted from above into the U-shaped holder 36, and at the same timethe brackets 40 of the tension slide are introduced into the recesses 77of the carrier element; the guide roller 81 is inserted in the passage13, so that the flanks 101 and 102 embrace the left end cover 6. Thecutting sheath is mounted in the guide roller, able to move lengthwiseand turn freely; the guide roller itself, however, can no longer moverelative to the cutting sheath after being inserted in the left endcover 6. The vacuum pressure-generating device is then inserted at oneend into the upward-open insert element 62 of the base block 8 by itsfree end 61 and at the other end into the U-shaped, upward-open passage16 by the connection piece 63. The connection piece 63 lies above theswitch pin 19.

Since the insert element at the base block has a clear width which justallows the inserting of the threaded spindle provided with surfaces 60at either end, the threaded spindle is held in the insert element,secure from turning. The toothed crown 55 of the threaded spindle nut 48engages with the take-off pinion 56 of the gear motor after beinginserted. The spacing between the base block at one end and the housingend cover 7 at the other is maintained so that syringe body 52 with thethreaded spindle nut 48 placed on the syringe body has just enough room.The unit formed by the syringe body and the mounted gear is held in thisway so that it cannot shift axially. After being inserted, the vacuumpressure-generating device lies parallel to the biopsy needle carrier;the connection element describes an arc of around 180°. It shouldfurther be noted that the inserting is done when the tension slide isnot cocked; this means that the gear 74 engages at the right end of thetoothed roller with the sample removal chamber open (FIG. 3). Afterbeing properly inserted, the housing cover can be closed. To facilitatethe inserting process, an insert aid can be used.

When the housing cover is closed, the connection piece 63 is forceddownward and activates the miniature switch by the switch pin 19 builtinto the end cover of the housing. This activates the electrical system,which is indicated by blinking of the reset diode 91 on the front sideof the hand piece 1. The reset diode at first blinks green, which meansthat the positioning of the individual elements, i.e., the insertingprocess, is not yet finished; the DC gear motor 21 must first close thesample removal chamber 71 with the cutting sheath 3 (the sample removalchamber was partly opened during the inserting). This occurs by twistingthe threaded casing connected to the cutting sheath. The cutting sheathmoves to the left until the gear 74 comes to bear against the inside ofthe holder 36. After closing the sample removal chamber, the plasticdisk 78 bears against the holder 36 (inside). During this process, orbefore or after it, the DC gear motor 58 brings the syringe plunger 54to bear against the syringe bottom 51.

After the starting positions are reached for the vacuumpressure-generating device and the biopsy needle/cutting sheath, thecocking diode 94 and the sample removal diode 92 light up green, and thereset diode goes out. The operator must now decide whether to initiatethe cocking of the tension slide or to remove an additional sample,e.g., because he has already previously removed one tissue sample. Ifthe operator presses the cocking button 90, the cocking of the tensionslide is initiated; the cocking diode blinks green, the sample removaldiode 92 goes out. By pressing the cocking button, the electrical DCgear motor 21 receives current and the DC gear motor actuates thetoothed roller 23. The gear 74 meshing with the toothed roller 23 turnsthe spindle shaft and at the same time the cutting sheath 3 connected toit. Since the spindle nut 75 is press-fitted in the biopsy needlecarrier 37 and the gear 74 is supported by the plastic disk 78 againstthe holder 36, which is firmly connected to the housing by the baseblock 8, the turning of the threaded spindle casing 73 has the effect ofmoving the biopsy needle carrier to the right.

At the same time, the biopsy needle 2 connected to the biopsy needlecarrier by the bearing element 49 is carried along, resulting in the tipof the biopsy needle moving into the cutting sheath. The biopsy needlecarrier 37 is moved to the right by the recess/bracket connection of thetension slide against the action of the spiral spring 31 until the lever33 of the locking element is forced into the recess 82 of the tensionslide by the spring 34. The tension slide is locked in this position.The gear motor receives the control command that the locking positionhas been reached, e.g., via a photocell installed in the sliding surfaceof the cover plate, which interacts with the retracted biopsy needlecarrier; the direction of turning of the motor is reversed and thecutting sheath is turned back to the right by the amount that thecutting sheath had moved beyond the tip of the biopsy needle by themovement of the tension slide and the biopsy needle.

At the end of this step, the cutting sheath completely closes the sampleremoval chamber (FIG. 11 d), as at the start of the cocking process. Thelocking diode 95 lights up green; the blinking of the cocking diode 94goes out. So as to reduce the friction between gear and support elementduring the cocking process, the plastic disk 78 is arranged between gear74 and holder 36. Now, the biopsy needle of the biopsy mechanism isinserted, for example, in a previously mounted coaxial cannula. Theproximal end of the mounted coaxial cannula receives a seal, designed sothat it seals off the space between cutting sheath and cannula, on theone hand, and allows an easy insertion of the biopsy needle with cuttingsheath, on the other. The seal ring prevents air from the outsidegetting sucked in through the space between cannula and cutting sheath.The seal ring likewise prevents fluid (cytological material) fromescaping after the biopsy needle is introduced or inserted. Thus, thepossibility of the disinfected hand piece 1 getting dirty is nearlyprecluded; on the other hand, the flank 101 of the sterile guide roller81 prevents the sterile cannula from getting dirty by reason of the handpiece 1. The tip of the biopsy needle is brought up in the cannula tothe tumor and, after being correctly positioned, thrust into the tumor.

The shot is triggered by pressing the activation button 88. This has theresult of swiveling the double-arm lever 33 about the axis 35 to releasethe tension slide. The tension slide is hurled to the left by springaction. The sample removal diode lights up green, the cocking diode goesout. By operating the program button 89, the sample removal sequence isenabled; the sample removal diode 92 blinks green. At first, the DC gearmotor 58 will activate the vacuum pressure-generating device. Theplunger of the vacuum pressure-generating device is moved in thedirection of the base block, i.e., away from the bottom of the syringe,until it reaches a position just before clearing the ventilationborehole 67 (FIG. 14 b). The vacuum is generated in the system. Afterreaching its end position, the system activates the motor 21, thecutting sheath which closes the sample removal chamber is opened via thegear/spindle drive. During the opening process, the partial vacuumprevailing in the system sucks in the tissue and any cytological fluid(cytological material) into the sample removal chamber. Cytologicalfluid will also flow thanks to the vacuum into the biopsy needle cavityand the vacuum pressure-generating device.

It has proven to be advantageous to direct the partial vacuum by thestopper 79 primarily at the lower region, the lower side, of the sampleremoval chamber, and the stopper 79 will prevent or impede tissue fromgetting into the biopsy hollow needle. When the sample removal chamberis fully open—the tissue sample is accommodated in the sample removalchamber—the gear motor 21 is reversed and the sample removal chamber isclosed. By turning the cutting sheath, the tissue is separated by thecutting edge 72 of the sheath 3 during the closing process. In order toreliably cut through the tissue filaments, it is advantageous to movethe cutting sheath 3 beyond the distal end of the sample removal chamber(around 2 mm). In order to accomplish this, it is only necessary toprogram accordingly the microprocessor where the control data is kept.Because of the special configuration of the sample removal chamber andthanks to the vacuum applied, the tissue sample is held in the chamberwithout torsion, so that the tissue sample is not twisted or turned bythe rotating and lengthwise moveable cutting sheath 3 which surroundsthe biopsy needle on the outside, as described.

After the sample removal chamber is closed, the DC gear motor isactivated for the vacuum generating unit 5. The plunger 54 is firstretracted far enough to clear the ventilation opening (FIG. 14 c). Afterthe vacuum is dissipated in the system, the plunger travels toward thevacuum bottom until the ventilation borehole is again closed, in orderto prevent the outflow of bodily fluid (cytological fluid). The blinkingof the sample removal diode 92 goes out. The ejection diode 93 lights upgreen. The biopsy needle with closed sample chamber is extracted fromthe cannula. After the removal of the biopsy unit and providing a vesselto receive the tissue sample and fluid, the program button 89 is againoperated and the ejection diode 93 starts to blink. At first, the gearmotor 21 of the cutting sheath is operated to open the sample removalchamber roughly halfway. After this, the DC gear motor 58 of the vacuumpressure-generating device is activated. The turning direction of the DCgear motor 58 remains and the threaded spindle 53 with plunger moves inthe direction of the syringe bottom, so that now an excess pressure iscreated in the system. The plunger travels up to the plunger bottom, andthe actuating motor 58 is deactivated.

The gear motor 21 moves the cutting sheath back across the sampleremoval chamber after the plunger has reached the plunger bottom. Thanksto the excess pressure built up in the system, the sample is forced outunder pressure into a waiting laboratory vessel even when the sampleremoval chamber is halfway open, and at the same time the cavity of thevacuum pressure-generating device, the biopsy needle and the sampleremoval chamber is cleared of tissue particles and fluid. The ejectionof the sample when the sample removal chamber is around halfway open isso that the ejection of the tissue sample is assured and the tissuesample does not fall back into the chamber as a result of prematuredissipation of the excess pressure. The narrowing of the cavity of thebiopsy needle by the stopper 79, which prevents or impedes tissue fromgetting into the cavity of the biopsy needle, proves to be especiallyadvantageous when removing the sample, since the narrower cross sectionboosts the ejection pressure. The best ejection results were thereforeachieved with the sample removal chamber halfway open; i.e., the cuttingsheath clears half of the sample removal chamber. The excess pressurealso forces tissue fluid out of the sample removal chamber and cleansit.

After the sample removal chamber is fully open, the removal and cleaningis finished, and the ejection diode goes out. The reset diode 91 lightsup green. If no further samples are to be removed now, the housing coveris opened and the removable element 20 is taken out. When the housingcover 10 is opened, the system is deactivated by the miniature switch18. However, if an additional sample is to be taken from the same tissueenvironment, the operator presses the program button 89 and the resetdiode 91 starts to blink. The vacuum pressure-generating device, as wellas the cutting sheath, are again adjusted as described. At the end ofthe process, the reset diode 91 goes out and the sample removal diodelights up. The next steps of the process occur in the sequence alreadydescribed. The process can be repeated as often as desired. At the end,the operator need only decide whether to take another sample or toconclude the sampling and open the housing cover.

As already described, in order to enhance the operating safety, a delaycircuit can be provided for individual steps such as “cocking” and“ejection of sample”. Furthermore, the light-emitting diodes can havedifferent colors, so that one can distinguish between work in the tissueand that outside the tissue. If it is required to take the sample from alocation of the tumor that does not lie directly above or at the sampleremoval chamber after being inserted, i.e., it lies to the side, theposition of the sample removal chamber 71 can be turned by means of theknurled disk 80. So that the operator can recognize this radialpositioning of the sample removal chamber, a marking in the form of anotch 119 is made on the knurled disk, pointing upward when the openingof the sample removal chamber points upward. The biopsy needle is fixedin the particular position by the surfaces of the polygon 50 and theelastic forces in the carrier piece. The sampling process is the same asalready described.

After completion of the biopsy, the interchangeable element 20(vacuum/pressure device, biopsy needle/cutting device with all elementsarranged on it) is removed from the top after releasing the cover. Tomake it impossible to open the housing when the tension slide is cocked,a safety tab 84 is arranged on the biopsy needle carrier, which bearsagainst the left end surface 85 of the closure mechanism in the cockedcondition. In this way, the closure mechanism, moveable in the X-axis,can no longer be moved to the left into the open position and thus thedog 12 can no longer be taken out from the recess 45. On the other hand,the housing cover also cannot be closed if the carrier unit has beeninserted in the cocked condition, since the safety tab prevents thelatch from being introduced into its designated space. The surface 85 ofthe latch adjoins the safety tab. The battery charge diode 96 is turnedoff as soon as the housing cover is opened. When the cover is closed andthe insert element 20 is installed, the battery charge diode indicateswhether sufficient energy is available.

Basically, it is conceivable to control all steps individually by handfor the removal of a sample, as well as the cocking of the slide, etc.,by activating and deactivating the two gear motors. However, it isexpedient to group together the individual steps of the sequence andhave them run automatically, with only the following step initiated byactivating a switch. This semiautomatic method, as described above, hasproven to be especially advantageous.

Basically, there are two conceivable methods for detecting the actualvalues and comparing them to the nominal values. One method is based onmeasuring the lengthwise displacement of the threaded spindle as it ispulled out or pushed in, and measuring the axial displacement of thecutting sheath or the biopsy needle carrier. In order to detect thesechanges, photocells or miniature switches are arranged inside thehousing, in particular on the extension of the base block 8. Inaddition, a positioning finger 103 is mounted on the cutting sheath,while the free end 61 protruding from the plunger unit can be used as ameasuring point for the threaded spindle of the vacuumpressure-generating device; if the front edge of the biopsy needlecarrier is used as a measuring point with a photocell, no additionalpositioning finger is required. The embedded photocells are covered withsuitable transparent material in case of possible contamination. Thepositioning finger 103 engages with a slot in the biopsy needle holder.At appropriate places on the extension of the base block 8 there areprovided recesses 107, in which photocells or miniature switches areinstalled, which interact either with the free end 61 of the plungerspindle, the positioning finger 103, or an edge of the biopsy needlecarrier (see FIG. 15). These signals (actual value) are processed in theelectronics to form the control signals.

The other system is based on measuring the number of revolutions of theDC motors. In this case, a pickup is mounted on the shaft of the DCmotor, which interacts with a photocell mounted on the housing of the DCmotor. In this way, the number of revolutions of the motor is measured.Since the DC motors operate with a speed of around 10,000 to 12,000 rpm,depending on the load, and on the other hand the secondary planettransmission arranged at the take-off end which interacts with thespindle drive considerably reduces the number of revolutions, an exactlengthwise control is possible. The lengthwise displacement by thespindle drive is a constant value proportional to the operating speedand is therefore sufficient as a control signal for the lengthwisedisplacement. In order to precisely determine the position of thecutting sheath 3 as well as the plunger 54 at the start, i.e., afterinserting the removable element and closing the housing cover 10, the DCgear motor 58 rotates the plunger 54 until it strikes against thesyringe bottom and the DC gear motor 21 brings the drive of the cuttingsheath to a zero position by moving the gear 74 until it strikes againstthe threaded spindle nut 75. (The threaded spindle nut 75 abuts againstthe gear 74.) From this zero position, the individual steps are thencontrolled by comparing the settings and the actual values. Thenecessary cables from the measuring pickup to the electronics areaccommodated in the housing, as is the board with the electroniccomponents. A microprocessor arranged inside the housing, under thecover, with the setpoint values stored in it, controls the individualprocesses.

In order to enable easy insertion of the removable insert unit, theinsert aid shown in FIGS. 16 and 17 can be used. As FIGS. 16 and 17 showin particular, the biopsy needle carrier is enclosed by two brackets 108and axially fixed in the holder by an additional cross piece 109, sothat it comes to lie parallel to the vacuum/pressure device in theinsert aid. The vacuum pressure-generating device is likewise enclosedby the bracket 116 at one side and by the centrally arranged bracket 108on the other side. In addition, a pin 110 engages with the ventilationborehole 67. This ensures that the vacuum pressure-generating device isoriented parallel to the biopsy needle carrier (FIG. 1). The parts sooriented are fixed in the insert aid so that they can easily be insertedfrom above into the hand piece 1 by means of the holder piece 117. Sincethe parts come in a sterile package with the insert aid, theinterchangeable element 20 can be removed from the package withoutmanual contact and be inserted in a sterile manner into the hand piece1. The brackets are slightly slanted for easier lodging of the vacuumpressure-generating device and the biopsy needle carrier. Since theinsert aid is made of plastic, the installed parts can easily be held inplace by clamping, thanks to appropriate choice of the tolerance andflexibility.

The tip of the needle unit of the biopsy device can be placed directlyon the tissue being sampled and inserted into the tissue. It can beexpedient, however, to first position a coaxial cannula and thenintroduce the portion of the needle unit (consisting of biopsy needleand cutting sheath) protruding from the hand piece 1 of the biopsydevice into the coaxial cannula 125. In this case, one should make surethat, when the vacuum is created for sucking in the tissue sample, noair can get in from the outside into the space between the inner surfaceof the coaxial cannula and the outer surface of the needle unit. In thecoaxial cannula (FIG. 18) consisting of a tube 121 with cap 122 placedat the proximal end, the tube 121 at the proximal end has a seal element123 (e.g., a properly dimensioned silicone hose), into which the needleunit is placed. In order to insert the coaxial cannula, a spike 124 isconnected to the coaxial cannula 125. The spike 124 has a tip 126protruding beyond the distal end of the coaxial cannula in the insertingstate. The connection between coaxial cannula and spike is a screwfastening, for example, so that the spike cap is configured as a screwcap 127. The screw cap is screwed onto the proximal end of the cap 122.The tube of the coaxial cannula is held in the cap 122 by clamping, forexample. After inserting the coaxial cannula, the spike is removed andthe needle unit of the biopsy device (in the cocked condition) isintroduced and positioned in the coaxial cannula (FIG. 20). The distalflank 101 of the guide roller is placed on the proximal end surface 128of the cap. After the tension slide is released, the needle tip with thesample removal chamber is forced into the tissue to its full length.

The depth of penetration of the biopsy needle unit of the biopsy deviceis between 20 and 35 mm, depending on the selected size of needle. Ingeneral, it is 20 mm. In the case of small breasts or tumors lying justbelow the skin, the depth of penetration of the biopsy needle istherefore too deep, since the biopsy device is placed directly or bymeans of the guide roller onto the coaxial cannula and the depth ofpenetration cannot be changed at the device. The depth of penetration isdevice-fixed. In order to be able to use the same biopsy device with thesame biopsy needle and same depth of insertion and the same, i.e.,uniform coaxial cannula with same overall length and less depth ofinsertion, one or more spacing pieces 129 are placed medially onto thebiopsy needle prior to insertion; thus, these lie medially in front ofthe guide roller mounted in the housing and the proximal end surface 128of the cap 122. Thus, by introducing spacing pieces or a spacing piece,the depth of penetration can be changed for the same depth of insertionprovided in the device.

After inserting the spacing piece, the tip of the biopsy needle in thecocked condition no longer projects slightly from the coaxial cannula,as when no spacing piece is used, but rather lies in the coaxialcannula. The depth of penetration is thus reduced by the length L of thespacing piece (also see FIGS. 20 and 21). This does not impair thefunctioning of the sample removal chamber or the operation of thecutting sheath. For example, if a spacing piece of 10 mm is used with adepth of needle penetration of 20 mm, the depth of penetration will bereduced to 10 mm. Of course, the spacing piece can be made up of one ormore parts, i.e., when using spacing pieces of 5 mm thickness, twospacing pieces are necessary to reduce the depth of penetration by 10mm. The adding of spacing pieces or one spacing piece of correspondinglength offers the possibility of using a uniform coaxial cannulaincluding a uniformly added insertion spike 124 for various depths ofpenetration. The same result regarding a reduced depth of penetrationcould also be achieved by using caps of different height or by mountingthe spacing pieces on the cap, which is equivalent to the threaded-onspacing pieces.

LIST OF PARTS

-   -   1 hand piece    -   2 biopsy needle    -   3 cutting sheath    -   4 connection element    -   5 vacuum pressure-generating device    -   6 housing end cover (left)    -   7 housing end cover (right)    -   8 base block    -   9 housing lower piece    -   10 housing cover    -   11 locking latch    -   12 dog    -   13 passage    -   14 borehole    -   15 passage    -   16 passage    -   17 plug    -   18 miniature switch    -   19 switch pin    -   20 removable element    -   21 DC gear motor    -   22 wall    -   23 toothed roller    -   24 U-shaped space    -   25 wall    -   26 block    -   27 groove    -   28 tension slide    -   29 threaded borehole    -   30 bolt    -   31 spiral spring    -   32 end piece    -   33 double lever    -   34 pressure spring    -   35 axis    -   36 holder    -   37 biopsy needle carrier    -   38 boreholes    -   40 brackets    -   41 surface of tension slide    -   42 extension of surface    -   43 lower sliding surface    -   44 surface of block 26    -   45 recess    -   46 cover    -   47 plastic part    -   48 threaded spindle nut    -   49 bearing element    -   50 polygon    -   51 syringe bottom    -   52 syringe spindle    -   53 threaded spindle    -   54 plunger    -   55 gear (toothed crown)    -   56 drive pinion    -   57 board    -   58 DC gear motor    -   59 transverse plate    -   60 surfaces    -   61 free end    -   62 insert element    -   63 connector    -   64 outflow connector    -   65 recess    -   66 chamfer    -   67 ventilation borehole    -   69 piston/cylinder unit    -   70 needle tip    -   71 sample removal chamber    -   72 cutting edge    -   73 threaded spindle casing    -   74 gear    -   75 threaded spindle nut    -   76 seal element    -   77 recesses    -   78 plastic disk    -   79 stopper    -   80 knurled disk    -   81 guide roller    -   82 recess    -   83 metal part    -   84 safety tab    -   85 end surface    -   87 center rib    -   88 activating button    -   89 program button    -   90 cocking button    -   91 reset diode    -   92 sample removal diode    -   93 ejection diode    -   94 cocking diode    -   95 locking diode    -   96 battery charge diode    -   97 passage    -   98 passage    -   99 arm of the double-arm lever    -   100 part of the lever    -   101 flanks of the guide roller left    -   102 flanks of the guide roller right    -   103 position finger    -   104 axis    -   105 actuating device (vacuum)    -   106 actuating device (biopsy needle, cocking mechanism)    -   107 recesses    -   108 brackets    -   109 cross piece    -   110 pin    -   111 storage battery    -   112 plastic part    -   113 surface    -   114 separating plate    -   115 guide borehole    -   116 fastening    -   117 holding pieces    -   119 notch    -   120 edge of needle carrier    -   121 tube    -   122 cap    -   123 seal element    -   124 spike    -   125 coaxial cannula    -   126 tip    -   127 screw cap    -   128 end surface    -   129 spacing piece    -   L=length of spacing piece

1. A method for initializing a biopsy device, comprising: providing adurable drive and a disposable component, the durable drive having adetecting portion, the disposable component including a biopsy needlewith a sample chamber selectively covered by a sheath and a vacuum pumpcoupled in fluid communication with the biopsy needle; installing thedisposable component in the durable drive, the durable drive and thedisposable component engaging each other with a gear, and wherein thesample chamber initially is not covered by the sheath; detectinginstallation of the disposable component in the durable drive based onan engaging of the detecting portion with the disposable component; andcovering the sample chamber with the sheath upon detection of theinstallation of the disposable component in the durable drive.
 2. Amethod for controlling a biopsy device, comprising: providing a durabledrive and a disposable component configured to be driven by the durabledrive, the disposable component having a biopsy needle with a samplechamber selectively covered by a sheath and a vacuum pump coupled influid communication with the biopsy needle, the sheath being initiallyin a retracted position to uncover the sample chamber so that the samplechamber is open to visual inspection, and the durable drive comprising asensor for sensing installation of the disposable component; maintainingthe sheath in the retracted position with the sample chamber uncovered,before installing the disposable component in the durable drive;installing the disposable component in the durable drive; sensing theinstalling with the sensor, and automatically operating the durabledrive to position the sheath in a covered position wherein the sheathcovers the sample chamber; and maintaining the sheath in the coveredposition that covers the sample chamber after installing the disposablecomponent in the durable drive until after the biopsy needle is insertedinto a host.
 3. The method of claim 2, the visual inspection includingmanually holding a holder that is removed when installing the disposablecomponent in the durable drive.
 4. A method for installation of adisposable unit in a durable drive unit, the disposable unit having abiopsy needle and a vacuum pump coupled in fluid communication with thebiopsy needle, the biopsy needle having a sample chamber and a sheaththat selectively covers and uncovers the sample chamber, and the durabledrive unit comprising a sensor for sensing installation of thedisposable unit, the method comprising: providing the disposable unitwith the sheath initially in a retracted position that uncovers thesample chamber to permit inspection of the sample chamber before thedisposable unit is used in a biopsy operation, installing the disposableunit in the durable drive unit; sensing the installing of the disposableunit in the durable drive unit with the sensor; based on sensing theinstalling, driving the durable drive unit with the disposable unitinstalled, wherein the sheath is driven from the retracted position tocover the sample chamber; and maintaining the sheath in a coveredposition that covers the sample chamber, after driving the durable driveunit to cover the sample chamber, until after the biopsy needle isinserted into a host.
 5. A biopsy device, comprising: a disposable unitincluding a biopsy needle and a vacuum pump coupled in fluidcommunication with the biopsy needle, the biopsy needle having a samplechamber and a sheath that is configured to selectively cover and uncoverthe sample chamber; and a durable drive unit configured to beinteroperable with the disposable unit when the disposable unit isinstalled in the durable drive unit, wherein the sheath is in aretracted position with the sample chamber uncovered to permitinspection of the sample chamber prior to installation in the durabledrive unit, the durable drive unit having a sensor configured to detectinstallation of the disposable unit in the durable drive unit, thedurable drive unit being configured to automatically extend the sheathto cover the sample chamber when the installation of the disposable unitin the durable drive unit is detected by the sensor.
 6. The device ofclaim 5, the durable drive unit having a housing cover configured topush a portion of the disposable unit against the sensor to cause thedisposable unit to be detected.
 7. The biopsy device of claim 5, whereinthe vacuum pump is further configured to generate a positive pressure.8. A biopsy device, comprising: a disposable unit including a biopsyneedle and a vacuum pump coupled in fluid communication with the biopsyneedle, the biopsy needle having a sample chamber and a sheath that isconfigured to selectively cover and uncover the sample chamber; and adurable drive unit configured to be interoperable with the disposableunit when the disposable unit is installed in the durable drive unit,the disposable unit being provided with the sheath in a retractedposition with the sample chamber uncovered to permit inspection of thesample chamber prior to installation in the durable drive unit, thedurable drive unit is configured with an insertion mode in which thesheath is driven to cover the sample chamber prior to insertion of thebiopsy needle into a host, the durable drive unit having a cover toenclose the disposable unit, the durable drive unit having a sensorconfigured to detect installation of the disposable unit in the durabledrive unit, the cover being configured to push a portion of thedisposable unit against the sensor to cause the disposable unit to bedetected to initiate the insertion mode.
 9. The device of claim 8, thecover being configured to move a portion of the vacuum pump to actuatethe sensor to cause the disposable unit to be detected to initiate theinsertion mode.
 10. A biopsy device, comprising: a drive unit configuredto receive a replaceable biopsy needle carrier unit; the replaceablebiopsy needle carrier unit having a biopsy needle with a sample chamberconfigured for being selectively covered with a sheath and a vacuum pumpcoupled in fluid communication with the biopsy needle, the replaceablebiopsy needle carrier unit being configured to have an insertion mode inwhich the sample chamber is covered by the sheath and a load mode inwhich the sample chamber is uncovered; the drive unit including a powersource, a controller, and a load switch connected to the controller, thedrive unit configured to engage the replaceable biopsy needle carrierunit with a gear; the load switch configured to transmit aninitialization signal upon the connection of the replaceable biopsyneedle carrier unit to the drive unit; and the controller configured torespond to the initialization signal by placing the replaceable biopsyneedle carrier unit in the insertion mode.
 11. The device of claim 10,the drive unit having a cover with a surface, the surface of the coverbeing configured to dispose at least a portion of the replaceable biopsyneedle carrier unit against the load switch when the cover is closedwith the replaceable biopsy needle carrier unit in the drive unit toactuate the load switch.
 12. The device of claim 10, the replaceablebiopsy needle carrier unit having a removable holding device configuredto allow the replaceable biopsy needle carrier unit to be handled andinstalled in the drive unit.
 13. The device of claim 10, the replaceablebiopsy needle carrier unit including a holding device configured toallow the replaceable biopsy needle carrier unit to be handled andinstalled in the drive unit, the holding device being configured to beremoved from the replaceable biopsy needle carrier unit afterinstallation of the replaceable biopsy needle carrier unit in the driveunit.
 14. A biopsy device, comprising: a disposable unit including abiopsy needle, a vacuum pump and a sheath, the biopsy needle having asample chamber, the vacuum pump being coupled in fluid communicationwith the biopsy needle, and the sheath configured to selectively coverand uncover the sample chamber; and a durable drive unit with which thedisposable unit is interoperable when installed in the durable driveunit, the durable drive unit having a housing and a controller containedin the housing operably coupled to the disposable unit when thedisposable unit is installed in the durable drive unit, the sheathhaving a retracted position with the sample chamber uncovered, whereinthe sample chamber is not covered by the sheath prior to installation inthe durable drive unit, the durable drive unit having a sensorcommunicatively coupled to the controller to detect installation of thedisposable unit, the durable drive unit being configured toautomatically cover the uncovered sample chamber with the sheath whenthe installation of the disposable unit in the durable drive unit isdetected by the sensor.
 15. The biopsy device of claim 14, wherein: thesensor is an initialization switch; the housing having a housing cover,and the disposable unit is configured to be inserted in the housing whenthe housing cover is open, and the durable drive unit configured suchthat when the housing cover is closed with the disposable unit in thedurable drive unit a portion of the disposable unit presses against theinitialization switch to activate the controller to cause the sheath tocover the sample chamber.
 16. The biopsy device of claim 15, wherein thevacuum pump includes an elongate cylinder with an axis parallel to abiopsy needle axis, and wherein when the housing cover is closed withthe disposable unit in the durable drive unit, a portion of the elongatecylinder is engaged with the initialization switch to activate thecontroller.
 17. The biopsy device of claim 14, wherein the vacuum pumpincludes an elongate cylinder that is adjacent to the biopsy needle, theelongate cylinder being connected to the biopsy needle by a length offlexible tubing to facilitate communication of a pressure from theelongate cylinder to the biopsy needle.
 18. The biopsy device of claim17, wherein the flexible tubing is U-shaped and a portion of theU-shaped flexible tubing is configured to be located outside saidhousing after the disposable unit is inserted into the housing.
 19. Thebiopsy device of claim 17, the durable drive unit including a movableshooting device, wherein the biopsy needle is connected to the movableshooting device such that the biopsy needle is configured to move withthe shooting device relative to the housing and the elongate cylinder,the flexible tubing being sufficiently flexible to accommodate themovement of the biopsy needle.
 20. The biopsy device of claim 14,further comprising: the vacuum pump having an elongate cylinder and apiston that is sealed and movable inside the elongate cylinder togenerate a vacuum in the biopsy needle; a vacuum motor contained in thehousing, the vacuum motor having a drive gear; the piston having a rackand a toothed crown nut that is configured to mesh with the rack todrive the piston when the toothed crown nut rotates; and the drive gearof the vacuum motor being configured to mesh with the toothed crown nut.21. The biopsy device of claim 20, wherein the vacuum pump is configuredto fit into a recess in the housing and configured to place the drivegear and the toothed crown nut in mesh when the vacuum pump is placed inthe recess.
 22. The biopsy device of claim 21, the housing having ahousing cover, wherein the housing cover is configured to force thetoothed crown nut against the drive gear when the housing cover isclosed when the disposable unit is in the durable drive unit.
 23. Thebiopsy device of claim 22, wherein the housing cover is configured tomove a portion of the vacuum pump to actuate the initialization switchto activate the controller when the housing cover is closed.
 24. Thebiopsy device of claim 14, wherein: the housing has an end cover and ahousing cover, the housing cover being configured to be opened andclosed; and the sensor is a switch integrated into the end cover of thehousing.
 25. The biopsy device of claim 24, the housing cover beingconfigured to push a portion of the disposable unit against the switchto cause the disposable unit to be detected to initiate the automaticcovering of the sample chamber.
 26. The biopsy device of claim 24,wherein the disposable unit is configured for insertion into the housingwhen the housing cover is open, and the housing cover is configured tocause a portion of the disposable unit to press against the switch toeffect the automatic covering of the sample chamber when the housingcover is closed.
 27. A biopsy device, comprising: a disposable unitincluding a biopsy needle, a vacuum pump and a length of flexibletubing; the biopsy needle having a cutting sheath; the vacuum pumpincluding an elongate cylinder positioned adjacent the biopsy needle,the elongate cylinder having a vacuum port at an end thereof, theelongate cylinder having a piston sealed and movable in the elongatecylinder to generate a vacuum when driven; the length of flexible tubinginterposed in fluid communication between the biopsy needle at an endthereof and to the vacuum port of the vacuum pump; a movable shootingdevice connected to the biopsy needle, such that the biopsy needle isconfigured to move with the shooting device relative to the elongatecylinder, the flexible tube being sufficiently flexible to accommodatethe movement of the biopsy needle; a drive for driving the vacuum pumpand the biopsy needle; a controller coupled to the drive; a switchcoupled to the controller; and a housing configured to contain theswitch, the controller, the drive, the movable shooting device, and atleast a portion of the disposable unit, the switch being located on thehousing and configured to detect an installation of the disposable unitin the housing, wherein the switch is configured to transmit a signal tothe controller upon detection of installation of the disposable unit inthe housing, and the controller is configured to respond to the signalby controlling the drive to initialize the biopsy needle to an insertionmode where the biopsy needle is configured for insertion into andsubsequent sampling from a host.